[Bug gcov-profile/85299] New: [GCOV] "if(0) break;" is wrongly marked as executed when it is prefixed with an array declaration "int a[1];" and followed by "if(0) continue; break;" in gcov
yangyibiao at nju dot edu.cn
gcc-bugzilla@gcc.gnu.org
Mon Apr 9 09:59:00 GMT 2018
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85299
Bug ID: 85299
Summary: [GCOV] "if(0) break;" is wrongly marked as executed
when it is prefixed with an array declaration "int
a[1];" and followed by "if(0) continue; break;" in
gcov
Product: gcc
Version: 8.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: gcov-profile
Assignee: unassigned at gcc dot gnu.org
Reporter: yangyibiao at nju dot edu.cn
CC: marxin at gcc dot gnu.org
Target Milestone: ---
$ gcc pv
gcc: error: pv: No such file or directory
gcc: fatal error: no input files
compilation terminated.
root@localhost:~/ccv# gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/8/lto-wrapper
OFFLOAD_TARGET_NAMES=nvptx-none
OFFLOAD_TARGET_DEFAULT=1
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu
8-20170923-1ubuntu2' --with-bugurl=file:///usr/share/doc/gcc-8/README.Bugs
--enable-languages=c,c++,go,brig,fortran,objc,obj-c++ --prefix=/usr
--with-gcc-major-version-only --program-suffix=-8
--program-prefix=x86_64-linux-gnu- --enable-shared --enable-linker-build-id
--libexecdir=/usr/lib --without-included-gettext --enable-threads=posix
--libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu
--enable-libstdcxx-debug --enable-libstdcxx-time=yes
--with-default-libstdcxx-abi=new --enable-gnu-unique-object
--disable-vtable-verify --enable-libmpx --enable-plugin --enable-default-pie
--with-system-zlib --enable-objc-gc=auto --enable-multiarch --disable-werror
--with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32
--enable-multilib --with-tune=generic --enable-offload-targets=nvptx-none
--enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu
--target=x86_64-linux-gnu
Thread model: posix
gcc version 8.0.0 20170923 (experimental) [trunk revision 253118] (Ubuntu
8-20170923-1ubuntu2)
$ cat small.c
void main() {
for (;;) {
int a[1];
if (0)
break;
if (0)
continue;
break;
}
}
$ gcc -w --coverage small.c; ./a.out; gcov-8 small.c; cat small.c.gcov
File 'small.c'
Lines executed:100.00% of 4
Creating 'small.c.gcov'
-: 0:Source:small.c
-: 0:Graph:small.gcno
-: 0:Data:small.gcda
-: 0:Runs:1
-: 0:Programs:1
1: 1:void main() {
-: 2: for (;;) {
-: 3: int a[1];
-: 4: if (0)
1: 5: break;
-: 6: if (0)
-: 7: continue;
1: 8: break;
-: 9: }
1: 10:}
Line #5 is wrongly marked as executed.
When we replacing Line #7 "if(0) continue;" with "if(0) break;", the result is
correct.
More information about the Gcc-bugs
mailing list